The present invention provides an integrated system for complete trash compactor operation due to a “smart” control mechanism that also combines operational monitoring of the compaction operation including the operational condition and performance of the compactor as well as the need for maintenance—beyond fullness monitoring.
In various commercial, residential and industrial locations, it is common to use waste compactors for compaction of garbage and other trash or waste materials being disposed of. Such waste compactors often comprise a trash container, a hydraulic ram operative in compacting strokes for compacting the waste placed in the hopper of a container, and a hydraulic pump operative for advancing and retracting the ram in such manner that the hydraulic pressure is capable of being sensed between the pump and the ram.
Traditionally, waste producers contract with waste haulers to pick up and haul away accumulated waste. If the pick up is made too late, the container can pack out. If the pick up is made too early, then the cost of waste hauling is unnecessarily high.
In order to optimally time the pick up of a waste container and thereby prevent the waste compacter containers from packing out or otherwise interfering with the operation of the business or industry associated with the compactors, various systems have been established to arrange for the containers to be emptied prior to packing out. In particular, monitoring systems have been used in order to monitor the fullness of the containers. Oftentimes, the monitoring systems include a communication link to a remote computer, so that the remote computer may centrally manage the containers.
The present invention provides for not just remote monitoring, but remote diagnostics, as well. Such remote diagnostic capabilities include: hopper door open or closed; motor starter; and/or high oil temperature warnings and the like. The unit of the present invention itself can transfer such real-time diagnostic information with or without a central computer by SMS text message or email, to a recipient's cellular or wireless phone or a wireless device such as a PDA or computer capable of receiving such wireless communication messages. In that way, a critical condition or warning can be sent directly from the controller/monitor of the Packer Plus™ device of the present invention to the intended recipient in real time, so that any such operational or maintenance need of the compactor device can be addressed in a timely manner so as to proactively avoid problems caused by a failure to do so.
A prior art automated trash compactor system of Burgis, U.S. Pat. No. 4,953,109, unlike the present invention, uses a motor current sensor to generate ram forward and ram return signals. The ram return signal is generated when the current to the electric motor exceeds a predetermined value.
In contrast, the compactor control system of the present invention uses a hydraulic pressure transducer placed in the supply line to the shuttle valve and lacks pressure relief valves and/or limit switches found on conventional compactors.
At least one prior system for managing waste compactors is disclosed in U.S. Pat. No. 5,299,493 to Durbin. Generally, in at least one embodiment of such a system, fullness monitoring is accomplished by monitoring the amount of force or hydraulic pressure over one or more strokes of the hydraulic ram during the compaction operation. The sensed pressure is then analyzed and a maximum generated signal pressure value is compared against set threshold values to determine the level of fullness of the container. If the maximum generated signal pressure value exceeds the maximum set threshold value, the monitoring system initiates a pick-up request.
However, while prior monitoring systems have monitored the fullness of containers, such systems have not combined such monitoring with controlling operation, much less how various factors, including the climate, the type and age of the equipment, and the control system, can affect the operation of the waste compactors and, in particular, the hydraulic rams and associated pressures. Accurately determining or calculating the pressures associated with particular compactors is particularly important to prevent damage to the hydraulic ram. In particular, during extend and retract strokes, if the system is not properly set, the hydraulic ram may contact or “bang” at the end of the stroke due to bottoming out, thereby potentially damaging the hydraulic ram and/or other features of the compactor, and thereby decrease the life and the functionality of the of the ram and/or other system components.
Additionally, while known to use hydraulics, present systems do not account for viscosity changes that affect the ram velocity and pressure measurements, and therefore ram extension/retraction travel time. Such viscosity changes may occur for a variety of reasons including extreme temperature variations or frequent use of the compactor resulting in the heating of the hydraulic fluid.
Therefore, there is a need to produce a trash compactor controller/monitor system that controls the operation of the compactor, while permitting the fullness pressures to be calculated for the particular container and allowing for periodic real-time oil viscosity measurements to account for changes in viscosity, while being economical and easy to manufacture.
Indeed, the present invention actually employs the following technologies: one which controls the operation of the compactor based on “learned” empirical time constants and a hydraulic pressure transducer placed in the supply line to the shuttle valve; a second which performs periodic real-time oil viscosity measurement so as to allow the system to adjust the “learned” empirical constants, as needed; and the monitoring of the operation of the compactor and fullness of the container, as disclosed in U.S. Pat. No. 6,738,732 to Durbin et al.